DTC 314 — Engine Oil Pressure Below Critical Level — International DT466E

DTC 314 on International DT466E (1996–2003) indicates engine oil pressure has dropped below the critical level and the ECM may be programmed to shut down for…

Updated October 15, 2026

What it means

Engine oil pressure has dropped below the critical level. On this platform the engine may be programmed to shut down.¹

Most likely causes

1. Actual low engine oil pressure due to low oil level, oil loss, or a mechanical oil-pressure problem — Verify oil level and actual oil pressure with a mechanical gauge before assuming a sensor fault. Stop the engine if pressure is critically low.¹
2. Faulty engine oil pressure (EOP) sensor or wiring causing a false low-pressure reading — A sensor-circuit fault can mimic low pressure. Compare mechanical gauge pressure to ECM-reported pressure; check EOP sensor signal and wiring integrity.²
3. Engine protection shutdown active due to sustained low oil pressure — The ECM can warn, derate or shut down for low oil pressure (DTC 313/314) depending on programming.¹

How to diagnose

1. Confirm the code with a Navistar scan tool or flash-code read; DTC 314 is a Navistar three-digit code, not an OBD-II P-code.
2. Stop the engine if it is running and check engine oil level; add oil if low and inspect for external leaks.
3. Install a mechanical oil-pressure gauge and compare actual pressure to specification at idle and at speed; if pressure is critically low, do not continue running.
4. If mechanical pressure is normal but DTC 314 persists, inspect the EOP sensor and its wiring for opens, shorts, or poor connections; compare ECM-reported pressure to mechanical gauge.
5. Check related engine-protection codes (e.g., DTC 313 for warning level) and ensure no other faults are contributing to shutdown.
6. Clear codes after repairs and retest oil pressure under load to confirm the fault does not return.

Parts and tools you may need

• Mechanical oil-pressure gauge
• Navistar-compatible scan tool or flash-code reader
• Basic hand tools for sensor and wiring inspection

Tools you’ll need

• Navistar-compatible diagnostic scan tool — Reads DTC 314 and live EOP data to confirm the fault and monitor engine protection status.
• Mechanical oil pressure gauge with appropriate adapters — Provides actual engine oil pressure at idle and speed to verify true pressure versus ECM reading.
• Digital multimeter — Tests EOP sensor supply, ground, and signal circuits for opens, shorts, or poor connections.
• Engine oil level dipstick and fill equipment — Confirms correct oil level and allows adding oil or inspecting for external leaks before mechanical testing.

Rough cost and difficulty

Typical US independent-shop figures; labor runs about $140–$200 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

Stop the engine immediately if mechanical oil pressure is critically low. Do not attempt to diagnose or repair high-pressure oil injection components. Seek a qualified diesel technician for internal engine diagnosis and repair.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources